1. Field of the Invention
The present invention relates to a jet-propulsion watercraft such as a personal watercraft (PWC) which ejects water rearward and planes on a water surface as the resulting reaction. More particularly, the present invention relates to a jet-propulsion watercraft comprising a device that can maintain steering capability even when the throttle is operated in the closed position and propulsion force is thereby reduced.
2. Description of the Related Art
In recent years, so-called jet-propulsion personal watercraft have been widely used in leisure, sport, rescue activities, and the like. The jet-propulsion watercraft is configured to have a water jet pump that pressurizes and accelerates water sucked from a water intake generally provided on a bottom of a hull and ejects it rearward from an outlet port. Thereby, the watercraft is propelled.
In the jet-propulsion watercraft, a steering nozzle provided behind the outlet port of the water jet pump is swung either to the right or to the left, to change the ejecting direction of the water to the right or to the left, thereby turning the watercraft to the right or to the left.
In the above-described jet-propulsion watercraft, when the throttle is moved to a substantially full closed position and the water ejected from the water jet pump is thereby reduced, the propulsion force necessary for turning the watercraft is correspondingly reduced, and the steering capability of the watercraft is therefore reduced until the throttle is re-opened.
To solve the above-described condition, the applicant disclosed a jet-propulsion watercraft comprising a steering component to mechanically create steering capability even when the throttle is moved to a substantially fully closed position and the water ejected from the water jet pump is thereby reduced (see Japanese Patent Application No. Hei. 2000-6708).
In the jet-propulsion watercraft comprising the above-described steering component, the number of parts is increased, which results in a complex structure and increased weight. As a solution to this, there has been proposed a jet-propulsion watercraft adapted to execute the control for increasing an engine speed to thereby allow the amount of ejected water to be maintained and the steering capability to be thereby maintained (herein referred to as “steering assist mode control”) when detecting a throttle-close operation of the throttle operation means and a steering operation of a steering operation means (see Japanese Patent Application Nos. 2000-6708, and 2000-142664, and 2000-142639) assigned to the same assignee as herein.